Toner and external additive for toner

Abstract

A toner includes toner particles and an external additive; the external additive includes an external additive A containing fine particles of a crystalline resin or fine particles of a wax; the crystalline resin and the wax each have an urethane bond or an urea bond; and the melting point of the crystalline resin and the melting point of the wax are each from 50° C. to 130° C.

What is claimed is: 
     
       1. A toner comprising:
 toner particles each containing a binder resin and a colorant; and 
 an external additive, wherein: 
 the external additive comprises an external additive A containing a fine particle of a crystalline resin or a fine particle of a wax, 
 the crystalline resin and the wax each have an urethane bond or an urea bond, and 
 the melting point of the crystalline resin and the melting point of the wax are each from 50° C. to 130° C. 
 
     
     
       2. The toner according to  claim 1 , wherein the crystalline resin has a peak molecular weight of from 15,000 to 60,000. 
     
     
       3. The toner according to  claim 1 , wherein the crystalline resin is a crystalline polyester. 
     
     
       4. The toner according to  claim 1 , wherein the melting point of the crystalline resin and the melting point of the wax are each from 55° C. to 130° C. 
     
     
       5. The toner according to  claim 1 , wherein the crystalline resin and the wax each have the urethane bond. 
     
     
       6. The toner according to  claim 1 , wherein:
 the external additive A is an organic-inorganic composite fine particle, 
 the organic-inorganic composite fine particle comprises: 
 (i) the fine particle of the crystalline resin, and an inorganic fine particle embedded in the surface of the fine particle of the crystalline resin, or 
 (ii) the fine particle of the wax, and an inorganic fine particle embedded in the surface of the fine particle of the wax, and 
 in the organic-inorganic composite fine particle, the inorganic fine particle is partially exposed to the surface of the fine particle of the crystalline resin or to the surface of the fine particle of the wax. 
 
     
     
       7. The toner according to  claim 6 , wherein the inorganic fine particle is at least one type selected from the group consisting of a silica fine particle, an alumina fine particle, a titania fine particle, a zinc oxide fine particle, a strontium titanate fine particle, a cerium oxide fine particle, and a calcium carbonate fine particle. 
     
     
       8. An external additive for toner, comprising:
 a fine particle of a crystalline resin or a fine particle of a wax, wherein: 
 the crystalline resin and the wax each have an urethane bond or an urea bond, 
 the melting point of the crystalline resin and the melting point of the wax are each from 50° C. to 130° C., and 
 the external additive for toner is an organic-inorganic composite fine particle, 
 the organic-inorganic composite fine particle comprises: 
 (i) the fine particle of the crystalline resin, and the inorganic fine particle embedded in the surface of the fine particle of the crystalline resin, or 
 (ii) the fine particle of the wax, and an inorganic fine particle embedded in the surface of the fine particle of the wax, and 
 in the organic-inorganic composite fine particle, the inorganic fine particle is partially exposed to the surface of the fine particle of the crystalline resin or to the surface of the fine particle of the wax. 
 
     
     
       9. The external additive for toner according to  claim 8 , wherein the crystalline resin has a peak molecular weight of from 15,000 to 60,000. 
     
     
       10. The external additive for toner according to  claim 8 , wherein the crystalline resin is a crystalline polyester. 
     
     
       11. The external additive for toner according to  claim 8 , wherein the melting point of the crystalline resin and the melting point of the wax are each from 55° C. to 130° C. 
     
     
       12. The external additive for toner according to  claim 8 , wherein the crystalline resin and the wax each have the urethane bond. 
     
     
       13. The external additive for toner according to  claim 8 , wherein the inorganic fine particle is at least one type selected from the group consisting of a silica fine particle, an alumina fine particle, a titania fine particle, a zinc oxide fine particle, a strontium titanate fine particle, a cerium oxide fine particle, and a calcium carbonate fine particle.